Photolithography is a method most widely used for forming various micro patterns such as a semiconductor, a thin film transistor, and a touch electrode, and is a method of obtaining a micro pattern after a material for forming a pattern is deposited on a substrate, and then a resist pattern corresponding to the pattern is formed by using a photoresist.
A typical method of forming a photoresist pattern by using a photoresist includes a film-forming process of applying a photosensitive resin composition for a photoresist on a deposition film of a material for forming a pattern, an exposure process of selectively irradiating a photoresist photosensitive resin film with light by using a mask prepared so as to correspond to a pattern to be formed, and a development process of obtaining a desired photoresist pattern by classifying the exposed region and the unexposed region to remove a region according to a positive system and a negative system.
In order to configure an electrophoresis display device, partition walls of the thus prepared photoresist pattern are filled with an ink, and a UV-curable adhesive, a heat-curable adhesive, a hot-melt-type adhesive, a pressure sensitive adhesive (PSA), or the like is typically used in order to bond the photoresist pattern to another base material. In this case, the UV-curable adhesive and the heat-curable adhesive have a problem in that it is difficult to apply the adhesive only on the partition wall, and since a high temperature of 100° C. or more should be applied to the hot-melt-type adhesive, the hot-melt-type adhesive has a problem in that a solvent included in an ink between the partition walls is volatilized when heated, and also has a disadvantageous effect in that the economic feasibility is insufficient because an expensive pressure sensitive adhesive is additionally needed when a photoresist pattern is bonded to a bonding surface of another base material by using a pressure sensitive adhesive.
Therefore, in order to solve the problems in the related art, there is a need for developing an pressure sensitive adhesive composition capable of simultaneously performing an pressure sensitive adhesive function while being capable of forming a pattern.
Korean Patent Publication No. 1997-0028792 relates to a photosensitive resin composition, and discloses a photosensitive resin composition consisting of a polymer conjugate, a photopolymerization initiator, and a photopolymerizable monomer including at least one terminal ethylenic unsaturated group, in which the photosensitive resin composition simultaneously contains photopolymerizable monomers represented by General Formulae (I), (II), and (III).
Korean Patent Publication No. 1997-0048906 relates to a photosensitive resin composition, and discloses a photosensitive resin composition containing at least one water soluble monomer having two or more unsaturated reactive groups capable of being addition polymerized and at least one water insoluble monomer as photopolymerizable monomers, in which the water soluble monomer is included in an amount of 3 to 15% based on solid content, and the total amount (#M) of the reactive groups of the photopolymerizable monomers is 0.5˜1.5 moles in 1 kg of the solid content.
Further, Korean Patent Publication No. 1999-0044707 relates to a dry film photoresist, and discloses a dry film photoresist prepared by sequentially laminating a protective film, a photosensitive polymer layer, and a support film, in which the protective film is a polyethylene terephthalate biaxially stretched film satisfying surface characteristics represented by Equation 1.
However, in the case of these documents, the pressure sensitive adhesive performance is not exhibited because a photoresist pattern should be bonded to another base material by heating the photoresist pattern to 100° C. or more in order to bond the photoresist pattern to the another base material and a material for forming the photoresist pattern has a high Tg, and the solvent component of an ink for an electrophoresis display device are not prevented from being volatilized.